Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Rental income		$ 1,588,400
Rental income			$ 1,380,422	$ 1,445,871
Total revenues		5,121,306	4,700,499	4,316,641
Expenses:
Property operating expenses		2,690,042	2,433,017	2,083,925
Depreciation and amortization		1,027,073	950,459	921,720
Interest expense		555,559	526,592	484,622
General and administrative expenses		126,549	126,383	122,008
Loss (gain) on derivatives and financial instruments, net		(4,399)	(4,016)	2,284
Loss (gain) on extinguishment of debt, net		84,155	16,097	37,241
Provision for loan losses		18,690	0	62,966
Impairment of assets		28,133	115,579	124,483
Other expenses		52,612	112,898	177,776
Total expenses		4,578,414	4,277,009	4,017,025
Income from continuing operations before income taxes and other items		542,892	423,490	299,616
Income tax (expense) benefit		(2,957)	(8,674)	(20,128)
Income (loss) from unconsolidated entities		42,434	(641)	(83,125)
Gain (loss) on real estate dispositions, net		748,041	415,575	344,250
Income (loss) from continuing operations		1,330,410	829,750	540,613
Net income		1,330,410	829,750	540,613
Less: Preferred stock dividends		0	46,704	49,410
Less: Preferred stock redemption charge		0	0	9,769
Less: Net income (loss) attributable to noncontrolling interests	[1]	97,978	24,796	17,839
Net income (loss) attributable to common stockholders		$ 1,232,432	$ 758,250	$ 463,595
Average number of common shares outstanding:
Basic (in shares)		401,845	373,620	367,237
Diluted (in shares)		403,808	375,250	369,001
Basic:
Income (loss) from continuing operations (in USD per share)		$ 3.31	$ 2.22	$ 1.47
Net income (loss) attributable to common stockholders (in USD per share)		3.07	2.03	1.26
Diluted:
Income (loss) from continuing operations (in USD per share)		3.29	2.21	1.47
Net income (loss) attributable to common stockholders (in USD per share)		$ 3.05	$ 2.02	$ 1.26
Resident fees and services
Revenues:
Revenue from contract with customer		$ 3,448,175	$ 3,234,852	$ 2,779,423
Interest income
Revenues:
Revenue from contract with customer		63,830	55,814	73,811
Other income
Revenues:
Revenue from contract with customer		$ 20,901	$ 29,411	$ 17,536

[1] Includes amounts attributable to redeemable noncontrolling interests